The latest figures from the Ministry of Health show men average around 22g of fibre a day, but need at least 30g. Women consume 18g, well short of their 25g target.

"We've known for a long time that on the whole people don't get enough fibre," said Ms Hanrahan.

According to Diabetes NZ, 40 Kiwis a day are diagnosed with type 2 diabetes.

The research - a meta-analysis of previously conducted research and health data - was carried out by Deloitte Access Economics and Nutrition Research Australia. While it was funded by Kellogg's, which includes All-Bran, Sultana Bran and Special K amongst its brands, Ms Hanrahan says the findings can be trusted.

"It's several layers removed from Kellogg's. Deloitte did the analysis, Kellogg's had nothing to do with the studies that are being analysed," she told Newshub.

"They've been quite transparent about that. It would be more concerning if they hadn't said they'd paid for it."

What cereal should I choose?

But picking the right cereal can be tricky, no matter the manufacturer. While many claim to be high in fibre, it's hard to resist the temptation to go for something a little higher in sugar.

Take Kellogg's All-Bran, for example. One serving of 40g contains about 42 percent of the daily recommended amount of fibre, while its arguably tastier variant All-Bran Honey Almond has half the fibre, but 43 percent more sugar.

All-Bran comes in a number of varieties.
Photo credit: Newshub.

Ms Hanrahan says the trade-off might be worth it, if that's what it takes to get more fibre into your system. Fibre, particularly grains, slow the body's absorption of sugar.

"You get less spikes in insulin, which makes type 2 diabetes easier to manage."

She adds that fibre also helps you feel full, so you may end up eating less overall and drop a few kilos, or stay a healthy weight - a good way to lessen the risk of type 2 diabetes.

"Swap your breakfast cereal to a high-fibre breakfast cereal, look at the type of bread you're having and swap it over to a higher-fibre type of bread - that can really reduce your risk of type 2 diabetes in particular."

Some sugar content in cereals also comes from fruit, which in moderation, she says is just fine.

Froot Loops, or loopy for fruit?

If you think it's hard changing your own eating habits, spare a thought for parents who have to put up with kids' demands for products like Coco Pops and Froot Loops.

A recommended serving of either of those Kellogg's products contains only 2 percent of a person's daily fibre needs, and both are more than a third sugar.

Froot Loops - not fruity, lots of sugar.
Photo credit: Getty

Ms Hanrahan says kids can be taught to like less-glamourous options like Weet-Bix, or grain toast with a banana.

"We say to kids, 'Eat your vegetables and then you can have a treat.' What say, vegetables were the heroes? Vegetables are the things they look forward to? What say we change the language?

"If from a young age children... got used to bread with bits in it, that wasn't white? We need to maybe change the way we talk about food with kids."